Field of the Invention
The present invention relates, in general, to vehicle engine throttle controls.
A conventional internal combustion engine includes a carburetor or throttle body, a throttle plate mounted within the carburetor or throttle body and pivotal between full open and closed positions, an accelerator linkage connected between the throttle plate and an accelerator pedal, a return spring biasing the throttle plate to the closed position and a throttle lever connected to the throttle plate and the linkage for pivoting the throttle plate between the open and closed positions. In normal operation, depression of the accelerator pedal causes pivoting of the throttle lever and the throttle plate toward the open position thereby increasing the volume of air flow to the engine. When the vehicle is decelerated, the return spring pivots the throttle lever and the throttle plate toward the closed position decreasing the amount of air flow to the engine and gradually slowing the engine to idle speed. An unsafe operating condition can occur if the accelerator linkage, the throttle lever or the throttle plate sticks in the full open position.
The brake system used to slow the vehicle to a stop is independent of the engine throttle controls. In normal use, the operator utilizes the same foot to control the accelerator pedal and to activate the vehicle brakes, alternating between the pedals as needed. However, the brakes can be applied while the accelerator is depressed. This results in an unsafe operating condition, as well as increasing wear on the brakes, the engine, the transmission and the transaxle and causing excessive fuel consumption. Further, if the brakes are applied when the accelerator is in the full open position, they are normally insufficient to bring the vehicle to a stop.
Several attempts have been made to provide an override for a carburetor throttle in the event that the throttle is stuck in the full open position. Such overrides are activated when the vehicle brakes are depressed. It would be desirable to provide an improved brake activated carburetor override which is of simple construction, easy to install on most engines, is functional on fuel injection systems and throttle bodies, and positively drives the throttle plate toward the closed, idle position when the vehicle brakes are applied independent of the position of the throttle lever connected to the vehicle accelerator linkage.